Rana and sofie went on a 20 mile bike ride today. Each girl biked at her usual speed. How long did Sofie wait for Rana at. the end of the route?

Question

Sophie bikes S miles per hour. Her friend Rana is slower. Rana bikes r miles per hour.

Answer 1

Sophie road 5 mph for 20 miles

distance = rate of speed times time traveled

d = st

20 =5t

t = 20/5 = 4 hours

Rana road r mph for 20 mile

d=rt

20=rt

t =20/r

Sophie waited 20/r - 4 hours

20/r -4 = (20-4r)/r

if Rana road at 4 mph, Sophie waited (20-4(4))/r = 4/4 = 1 hour

If Rana road at 3 mph, Sophie waited (20-4(3))/3 = 8/3 = 2 hours 40 minutes

if Rama road at 2 mph Sophie waited (20-4(2))/2 = 12/2 = 6 hours

if Rama road 1 mph Sophie waited (20-4) = 16 hours